 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.resources;

 import java.net.URI ;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.*;

 /**
  * Object for describing the characteristics of linked resources that are stored
  * in the project description.
  */
 public class LinkDescription implements Comparable {

     private URI localLocation;

     /**
      * The project relative path.
      */
     private IPath path;
     /**
      * The resource type (IResource.FILE or IResoruce.FOLDER)
      */
     private int type;

     public LinkDescription() {
         this.path = Path.EMPTY;
         this.type = -1;
     }

     public LinkDescription(IResource linkedResource, URI location) {
         super();
         Assert.isNotNull(linkedResource);
         Assert.isNotNull(location);
         this.type = linkedResource.getType();
         this.path = linkedResource.getProjectRelativePath();
         this.localLocation = location;
     }

     public boolean equals(Object o) {
         if (!(o.getClass() == LinkDescription.class))
             return false;
         LinkDescription other = (LinkDescription) o;
         return localLocation.equals(other.localLocation) && type == other.type;
     }

     public URI getLocationURI() {
         return localLocation;
     }

     /**
      * Returns the project relative path of the resource that is linked.
      * @return the project relative path of the resource that is linked.
      */
     public IPath getProjectRelativePath() {
         return path;
     }

     public int getType() {
         return type;
     }

     public int hashCode() {
         return type + localLocation.hashCode();
     }

     public void setLocationURI(URI location) {
         this.localLocation = location;
     }

     public void setPath(IPath path) {
         this.path = path;
     }

     public void setType(int type) {
         this.type = type;
     }

     /**
      * Compare link descriptions in a way that sorts them topologically by path.
      * This is important to ensure we process links in topological (breadth-first) order when reconciling
      * links. See {@link Project#reconcileLinks(ProjectDescription)}.
      */
     public int compareTo(Object o) {
         LinkDescription that = (LinkDescription) o;
         IPath path1 = this.getProjectRelativePath();
         IPath path2 = that.getProjectRelativePath();
         int count1 = path1.segmentCount();
         int compare = count1 - path2.segmentCount();
         if (compare != 0)
             return compare;
         for (int i = 0; i < count1; i++) {
             compare = path1.segment(i).compareTo(path2.segment(i));
             if (compare != 0)
                 return compare;
         }
         return 0;
     }
 }

